1. Field of the Invention
The present invention relates to a solder mask configuration for a printed circuit board, and particularly to a solder mask configuration for a printed circuit board of a modular jack which improves breakdown voltage performance.
2. Description of Prior Art
During the manufacture of a printed circuit board, a solder mask, which remains on the printed circuit board when in use, is generally used to protect the circuitry and to provide insulation. FIGS. 4 and 5 show a printed circuit board 53 employed in a modular jack (not shown) and engaging with a first terminal insert 51 and a second terminal insert 52, respectively. The printed circuit board 53 has no solder mask thereon and only a conductive metal layer 533 coated on an inside surface of each terminal insertion hole 531 for electrically connecting with a press-fitted end 512 of a first terminal 511 of the first terminal insert 51 or a press-fitted end 522 of a second terminal 521 of the second terminal insert 52. The conductive metal layer 533 forms a base ring 535 on the printed circuit board 53, which is delimited by an outer perimeter 534 thereof. However, a relatively small increase in voltage using this printed circuit board configuration may result in arcing between adjacent base rings 535, because of a relatively short creepage distance Lxe2x80x2.
Hence, a printed circuit board having an improved breakdown voltage performance for use in a modular jack, is required.
The object of the present invention is to provide a printed circuit board which has an improved breakdown voltage performance for use in a modular jack.
In order to achieve the above-mentioned object, a printed circuit board in accordance with the present invention includes a plurality of terminal insertion holes defined therethrough. A conductive layer is coated on an inner surface of each terminal insertion hole. A solder mask covers portions of a front and rear surfaces of the printed circuit board between adjacent terminal insertion holes. The mask extends a distance into each terminal insertion hole. As a result, a creepage distance between adjacent holes is increased compared with that of the prior art.
A modular jack using such a printed circuit board comprises an insulating housing, with a first terminal insert and a second terminal insert assembled to the printed circuit board, the assembly of the board with first and second terminal insert being received in the insulating housing. A metal shield encloses the insulating housing. The printed circuit board further has a noise filter soldered thereon for EMI purpose. The first terminal insert comprises an insulative base with a plurality of terminals embedded therein and the second terminal insert comprises an insulative body with a plurality of conductive pins embedded therein. Each terminal and each conductive pin has a press-fitted end for being inserted into and electrically engaging with the corresponding terminal insertion hole.